1. Field of the Invention
This invention pertains to the field of 2-haloacetanilides and their use in the agronomic arts, e.g., as herbicides.
2. Description of the Prior Art
The prior art includes numerous disclosures of 2-haloacetanilides which may be unsubstituted or substituted with a wide variety of substituents on the anilide nitrogen atom and/or on the anilide ring including alkyl, alkoxy, alkoxyalkyl, haloalkyl, halogen, etc., radicals.
Swiss Pat. Nos. 579,348, 585,191 and counterpart Belgian Pat. No. 810,763 contain generic disclosures of N-alkoxyalkyl (wherein the alkyl moiety contains no less than two carbon atoms) -2-chloroacetanilides which may be substituted on the anilide ring at the ortho and meta positions with one or more radicals selected from a plurality of radicals including halogen, alkyl, alkoxy or trifluoromethyl (--CF.sub.3). In more particular, the list of compounds in Table I of the Swiss Patents (Table II of the Belgian Patent) includes species substituted with a --CF.sub.3 radical in one ortho position with no substituent in the other ortho position (Compound Numbers 37-48) and compounds having --CF.sub.3 substitution in a meta position with one ortho position unsubstituted and the other ortho position substituted with a methoxy radical (Compound Numbers 22-25) or a chlorine atom (Compound Numbers 33-36). In addition, the list includes species with a --CF.sub.3 radical in one ortho position and a --CH.sub.3 in the other ortho position (Compound Numbers 54-56). The compounds in these patents, however, are characterized by an alkoxyalkyl group substituted on the anilide nitrogen atom wherein the alkylene moiety must have no less than two carbon atoms between the nitrogen atom and the oxygen atom of the alkoxy moiety. In contrast, the compounds of this invention are characterized, in part, by the substitution on the anilide nitrogen atom with an alkoxymethyl radical.
The invention compounds have specified combinations of hydrocarbyloxymethyl radicals on the anilide nitrogen, a trifluoromethyl radical in one ortho position and methyl radical, an ethyl radical or hydrogen in the other ortho position. The significance of the differences between compounds of the above patents and compounds of this invention is shown by comparative herbicidal data herein.
U.S. Pat. Nos. 4,070,389, 4,137,070, 4,152,137, and Belgian Pat. No. 862,413 typify the use of very broad generic formulas that can include a huge number of components. These generic formulas can each include haloacetanilides that may be constructed by selection among the great many options available to contain one or more --CF.sub.3 and/or ring substituents, and/or nitrogen substituents. The specific compounds which are named in these patents, however, demonstrate that --CF.sub.3 was not a preferred substituent, particularly when the N-substituent was an alkoxyalkyl radical. On the contrary, it was virtually ignored. Despite the many compounds named in these patents, only one --CF.sub.3 containing haloacetanilide, viz., (2'-trifluoromethyl-.alpha.,.alpha.-di-chloroacetanilide) is identified (U.S. Pat. No. 4,137,070) and even that compound is not a monochloroacetanilide.
Although an additional substantial body of art relating to a variety of acetanilides exists, very few haloacetanilides of any kind were named which contained a --CF.sub.3 and these were almost always in the meta or para position. There is, of course, a very large body of prior art which is directed to haloacetanilides which makes no reference whatever to any --CF.sub.3 group.
Research continues in a never-ending effort to identify desirable herbicides. Herbicide properties which, inter alia, are the focus of research and development efforts include an ability to control or suppress a variety of weeds, an ability to provide reasonable crop safety at application rates, longevity under normal weather conditions, an ability to function in a plurality of soils, and an ability to be used in more than one application mode.
It is an object of this invention to provide herbicides which have good activity against a plurality of weeds.
It is a further object of this invention to provide herbicides which provide good crop safety, particularly in corn and soybeans.
It is another object of this invention to provide herbicides which may be used in a variety of soils.
It is still another object of this invention to provide herbicides which exhibit weed suppression over extended periods of time.
It is yet another object of this invention to provide herbicides which are non-toxic and do not require special handling procedures.
It is a still further object of this invention to provide herbicides which are capable of being used in a variety of application modes.
The above and other objects of the invention will become more apparent from the detailed description below.